Improved vulcanizing-flask for dentists



t i UNITED STATES PATENT OEEIcE.

*A L. HOFFSTADT, OF PHILADELPHIA, PENNSYLVANIA.

P IMPROVED VULCANIZING-FLASK FOR DENTISTS.

Specification forming part of Letters Patent No. 57,135, dated August14, 1866.

- To all 'whom it may concern:

Be it known that 1, L. HoEEsTADT, of No.' 159 Brown street, in the cityof Philadelphia, count-y of Philadelphia, and State of Pennsylvania,have invented a new and Improved Apparatus for Vulcanizing India-Rubber,&c.; and I do hereby declare that the following is a full, clear, andexact descriptionthereof, which will enable others skilled in the art tomake and use the same, reference being had to the accompanying drawings,forming part of this specification, in which- Figure 1 represents afront elevation of this invention. Fig. 2 is a plan or top view of thesame. Fig. 3 is a vertical section of a portion ofthe same.

Similar letters of reference indicate like parts.

This invention consists in the arrangement of a self-actin g regulator,in combination with a vulcanizin g apparatus, in such a manner that bythe action of said'regulator the flame which heats the boiler of thevulcanizing apparatus is extinguished when the temperature rises beyonda certain degreee, or regulated according to the temperature in saidboiler.

The regulator is placed in a circular recess in the top of the boiler,and it is composed of a segmental ring made of different metals, so thatthe same expands and contracts by the heat, and its loose end acts on alever which carries an index, whereby the temperature existing in theboiler can be read off. Said lever is provided with an adjustable screw,the point of which strikes and disengages a levercatch whenever thetemperature in the boiler rises beyond a certain degree, and by said1ever-catch the flame which heats the boiler is extinguished, or atleast regulated, and all danger of an explosion is avoided.

The top edge of the boiler is strengthened by a flange or rim on whichthe cover rests, and said cover is fastened down by hookshaped screwswhich catch under the ange or rim, and which can be readily attached ordetached.

A represents a boiler of that class which are generally used by dentistsin their vulcanizing operations. This boiler is placed into a jacket, B,of sheet meta-l or other suitable material, and it is heated by agas-flame to which gas is admitted through the pipe C. A stopcock, D,regulates the supply of the gas. If

desired, however, a kerosene lamp or any other flame may be used for thepurpose of heating the boiler.

The top edge of the boiler is strengthened by a flange, a, whichprojects over the edge of the jacket, and which forms the support forthe cover E. This cover is fastened down by hooked-shaped screws b,which catch under the flange a, and which are readily fastened andunfastened.

The cover E is provided with a circular recess, c, which is intended toreceive the regulator F. This regulator is composed of a segmental ringmade of two strips of different kinds of metal, which are put togetherin such a manner that the ring has a tendency to straighten out by theaction of the heat. The ring is fastened down tothe cover by one or morescrews passing through one of its ends, and its loose end bears on theshort arm of a spring-lever, d, which has its fulcrum on a screw, e, andthe long arm ot' which extends through a slot, f, in the dial G andworks in the slotted end of an index-hand, g. This index traverses overa scale which is marked to indicate the temperature existing in theboiler.

For the purpose of marking the scale an ordinary thermometer isintroduced into a cavity made for that purpose in the cover E, which,when the scale is complete, can be covered up by a suitable cap.

Through the long arm of the spring-lever d passes a set-screw, h, whichis so adjusted that its point releases the lever-catch H. This catchextends from an arm, t', projecting from the plug of the stop-cock D,and it can be made to catch over the edge of that part of the cover Ewhich supports the spring -lever d. If the lever-catch is thus adjustedit retains the stop-cock in such a position that the gas has free accessto the burner; but if the lever-catch is released it drops down by itsown gravity and the stop-cock is closed.

In order to call the attention of the operator to the fact that the gashas been shut off a small hammer, m, is connected to the plug of thestop-cock, and said hammer is caused to strike a bell, n, whenever thelevercatch is released and caused to drop down.

It desired, the lever-catch may be made to act on the wick-tube of alamp or on a suitable regulating device, so that when a kerosene-lamp isused for the purpose of heating the boiler the supply of oil or the sizeof the ame is regulated automatically by the action of the regulator F.

By this arrangement an apparatus for vulcanizing articles ofindia-rubber or other vulcanizable gums is obtained which is cheap,easily operated, and free from all danger of explosion.

Having thus described my invention, I claim as new and desire to secureby Letters Patentl. Providing the boiler A with a flange, ct,

in combination With the cover E and hookshaped screws b, constructed andoperated substantially as and for the purpose described.

2. The regulator F, in combination with the boiler A and dial G,constructed and operating substantially as and for the purpose setforth.

3. The lever catch H and stop -cock D, in combination with the regulatorF, adjustable screw h, aud boiler A, constructed and operatingsubstantially as and for the purpose described. Y

4. The regulator F, boiler A, lever-catch H, stop-cock D, hammer m, andybell n, all constructed and operating substantially as and for thepurpose set forth.

Y Y LEWIS HOFFSTADT. Witnesses:

GHAs. S. JONES, ELI T. STARR.

